Fuel Pressure Regulator

[Guest]

Anyone know the part number for the 3.0Bar Bosch FPR, with the screw fit NOT the push fit??? Where is best place to get one, how much..

Cheers.

 

[hawkhead]

There has just been a big discussion about this on the Titanic mailing list http://www.titanic.co.uk/944

Try here http://www.promaxmotorsport.com

 

[Guest]

A bit much to be paying for one, was looking for a direct replacement for the bosch one but 3bar not 2.5bar.

Cheers

 

[944Turbo]

I have been looking into this but don't actually have the parts yet, the Porsche part is the same for late S2 and 968 - part number 944.110.19806. I spoke to the Bosch technical department, their part number is 0280 160 287 this is apparently a 3.8 bar regulator. The price from porsche is approx £85. I will be trying my Bosch dealer and see how much it is from there, unless the price is a lot better though I will proabably go adjustable but then the lindsey racing fuel rail gauge will probably become essential.

Tony

 

[Diver944]

I have the push fit 3 bar FPR on my Turbo, yet when my mechanic measured the fuel pressure at idle it was in fact 3.8 bar?? [&:] So why they call it a 3 bar FPR I do not know.

FYI apparently the 2.5 bar standard FPR measures at 2.8 bar at idle - confusing isn't it???

 

[Guest]

Well i am going to the OPC tomorrow so will have a wee nosey and see what price they can come up with.

 

[Guest]

Yip £85 for it from OPC.

Will give Bosch a phone on Monday see what price from them.

 

[Guest]

Well i got a price of £48 + vat from my local Accesories place for it.

 

[Guest]

Tha saga continues, seems that using the 968 3.8bar regulator is not a good idea. I have spoken to Bosch Technical and they are looking into it for me to see if they do a 3.0bar version of the screw type FPR. I am not holding my breath. I suppose the other answer is to just cut the pipe and use a jubilee clip to hold it on, but thats seems abit drastic at this early stage.

Any thoughts?

 

[Fen]

I saw your thread on Rennlist - quite interesting. As for options:

Adjustable FPR with fuel rail gauge?

Danno's adapter?

Change the pipe to one from an earlier car and save the original one intact with the original FPR?

 

[944Turbo]

Why did they think it was a bad idea? It might be worth asking what pressure is a
0 280 160 249 as this is the push fit part that Guru supply - I believe the one Paul (Diver944) has that seems to produce 3.8 bar (when measured) even though its sold as 3.0 bar.
Tony

 

[Fen]

The info comes from Danno. See here

 

[Guest]

Change the pipe to one from an earlier car and save the original one intact with the original FPR?

That might just be the best solution yet to be honest. Its a real pain casue the onl ytime i can get to looka t thecar is the weekend when its light, so it take a full week before anything can get done. I assume the pipe is fairly easy to fit. i.e. i dont have to go under the car (or need a ramp) If so i might order a pipe for a per 90 car from OPC and go down that route.

The plot thickens. I am still not convinced about all the tech stuff that is flying about, unfortunatly i dont know enought about it.

 

[Fen]

The more I think about it the more confused I become.

I can see that a pump has to be more powerful to maintain a given flow rate at a higher pressure but surely if it maxes out with a 3.8 bar regulator it will flow it's max volume at a pressure of less than 3.8 bar, not achieve 3.8 bar but flow less volume? Net result is the same in that it doesn't supply sufficient fuel into the cylinder though.

I was reading Danno's description (admittedly 18 months old) of how a boost enhancer works and his understanding of pressure was plain wrong (here if you're interested) which makes me slightly cautious about believing him on technical stuff. That said I trust that he has seen the results he says he has on dynos and his chips work successfully with a 3 bar regulator.

I guess I just mentally added a new fuel pump to my (growing) list of mods...

 

[Guest]

So the best solution would be to keept hestandard FPR (might not get full performance ) but atleast will get proper fuel supply and not over stress the fuel pump.

That sounds like the safest option to me untill the regulator can be found. Or the pipe changed as you suggested.

 

[944Turbo]

Thanks Fen, interesting Im not going to even attempt to get my head round what the lambda sensor in the exhaust will try and do if it sniffs rich or lean mixture - maybe danno ignores it anyway with his maps - I am more certain that I want to fit an AF ratio meter before the chips though now.
Tony

 

[Fen]

ORIGINAL: slim_boy_fat

So the best solution would be to keept hestandard FPR (might not get full performance ) but atleast will get proper fuel supply and not over stress the fuel pump.

That sounds like the safest option to me untill the regulator can be found. Or the pipe changed as you suggested.

Potentially that would underfuel for the boost. The chips are coded to expect 3.0 bar so will operate the injector duty cycle to suit.

That said my car was set up on a rolling road with a custom map (by Bob Watson) and he was surprised that the standard fuel system was sufficient. The difference there was that he tailored the duty cycle of my injectors to suit what I had. In other words the stock system may well be enough, but Danno has blown the chips to suit increased fuel pressure so they aren't set up expecting the stock set up.

 

[944Turbo]

Its also interesting that our moderator (unless I am mistaken) has a Danno supplied push fit 3 bar FPR and yet it gives 3.8 bar fuel pressure when at Idle.
I am reasonably certain Wayne at chip wizards also recommends the S2 FPR if you do not fit an adjustable unit when running the DPW (or squeezing the 2.5bar unit in a vice but thats not add that complication!). The other thing I have been thinking about is how does the damper on the other end of the fuel rail affect things?

Questions, questions, questions .........
Tony

 

[Diver944]

ORIGINAL: 944Turbo
Its also interesting that our moderator (unless I am mistaken) has a Danno supplied push fit 3 bar FPR and yet it gives 3.8 bar fuel pressure when at Idle.

Wow, I haven't got time to digest all this just now [&:] but I've just been out with a torch (in the rain [8|] ) to double check and my Danno supplied FPR is marked as 3.0 Bosch which is the same as on my S2.

I've just read section 24-104 of the factory workshop manuals for 944 S2 and it does say that with the DME bridged to make the fuel pump run permanenetly, but with the engine STOPPED the FPR should read 3.8 bar, at IDLE it should read 3.3 bar.

My garage told me I was making 3.8bar and I just presumed that was at idle, I am willing to bet now they were talking about the former - apologies if I have caused confusion [&:]

 

[Guest]

So you have the S2/968 FPR on yours anyway without any problems?

And it actually runs at 3.3bar at idle! So does this mean that the 3.0 bar ones would run 2.5-2.6 at idle?

More questions.

Surely 3.3bar would be fine to use. Considering all the other possible restrictions and inconsistencies 0.3bar extra is not much.

All the way back round to just fitting the S2 FPR again.

Round and round we go!!